I. Field of the Invention
The present invention relates generally to the field of water treatment. More particularly, it provides a variety of compositions and methods for use in the removal of biological pathogens from water using Surfactant-Modified Zeolite (SMZ).
II. Description of Related Art
It is known that septic tanks, sewage effluents, and landfills can release microbial and viral pathogens into groundwater. Microbial contamination of drinking water is a serious problem with global significance (Pillai, 1998). In many countries around the world, including the United States, groundwater serves as a primary drinking water source. In the United States, groundwater provides approximately 40% of the water supply used for public consumption (Solley et al., 1985). In other countries such as Denmark, approximately 98% of the drinking water supply is obtained from groundwater (Czako, 1994). Groundwater is susceptible to fecal contamination from a variety of sources including leaking sewer lines, leaking septic tanks, infiltration of surface water contaminated by human and animal wastes, and careless disposal of septic wastes. It is estimated that between 1971 and 1994, there were as many as 342 disease outbreaks in the United States that were associated with contaminated groundwater (Rose and Yates, 1998). Microbial pathogens were shown to be responsible for almost 30% of these outbreaks (Cothern, 1992; Craun and Calderon, 1996).
Due to technological and other limitations, the causative agents for a majority of these disease outbreaks are still unknown, although clinical features suggest a viral etiology for most of these cases (CDC, 1993). Enteric pathogens can survive for extended periods of time in groundwater and can also migrate significant distances in groundwater (Keswick et al., 1982; Schaub and Sorber, 1979; Idelovitch et al., 1980; Rehmann et al., 1999; Woessner et al., 2001 Dowd et al., 1998). Adding to this concern, enteric viruses and certain bacterial pathogens such as Shigella spp. have relatively low infectious doses. Rose et al. (1997) have reported that the probability of infection resulting from one Hepatitis A or Rotavirus particle or Shigella cell are 42%, 27%, and 0.06% respectively. Inexpensive solutions for removing biological pathogens from water are urgently needed. The recent threat of bioterrorism and concerns for the safety of drinking water supplies further add to this urgency.